Current light duty liquid detergents are dramatically deficient in these areas. The consumer has to soak soiled items for long periods of time in these solutions, and then use harsh cleaning methods (scouring with steel wool or scouring cleanser) to remove the remaining soil.
To speed up the process and increase efficacy of cleaning these soils, the consumer will resort to heat, scraping and harsh chemicals (e.g. caustic oven cleaners).
Deficiencies in these cleaning methods include time consumption for soaking and scouring, physical effort required for scouring and scraping, irritation to hands from harsh cleaning chemicals and methods, damage to objects from harsh chemicals and methods, unpleasant fumes and odors and danger from heated solutions. Though non-caustic cleaners are listed in the literature, none are directed to the cleaning compositions of the present invention.
U.S. Pat. No. 4,575,530 (Mar. 11, 1986) describes hydrocarbon solution additives which are polyampholytes which incorporates cationic and anionic moieties on the same polymeric backbone. These hydrocarbon solutions have shear thickening properties.
U.S. Pat. No. 4,536,539 (Aug. 20, 1985) claims include increasing the viscosity of water under increasing shear rates (22.0--approaching 100 sec.sup.-1). This shear thickening behavior is primarily attributed to the increase in apparent molecular weight of the interpolymer complex through formation of intermolecular ionic linkages.
The instant patent teaches that these thickened silicates show shear thickening (dilatency), which is an increase in viscosity as shear rate is increased. Furthermore, the viscosity values at each shear rate are independent of the timescale of the experiment. Once the shear rate is applied, the viscosity reaches a steady value after a few seconds up to several minutes. Shear thickening occurs when the applied shear forces predominate the interparticle forces. The shear forces change the dispersion from a certain degree of order to clusters of particles. Shear thickening behavior is dependent on particle shape, size and size distribution; particle volume fraction; type and strength of inter-particle interaction; continuous phase viscosity and the experimental parameters characterizing the shear thickening. These parameters include the type, rate and duration of the applied shear deformation.